Shuttering element for the construction of a hemispherical building and method of shuttering in construction thereof

ABSTRACT

Shuttering elements ( 1, 20 ) for the construction of a hemispherical building are disclosed, comprising webs ( 10 ) along the side edges ( 4, 5 ) thereof. The webs ( 10 ) project from the underside ( 8 ) of the shuttering element ( 1, 20 ), facing what is to become the building interior ( 36 ). The individual shuttering elements ( 1, 20 ) may be connected using the webs ( 10 ), by means of quick-fasteners ( 12, 13 ) to produce the complete shuttering and are multiply re-usable. The invention further relates to a method for the construction of a hemispherical building.

[0001] Hemispherical buildings and dome-shaped structures, also called mound-type or earth-mound-type houses, have a number of advantages, for example, their high load capacity with low materials expenditure. On the other hand, they have the disadvantage of being relatively complex and expensive to construct. Since conventional shuttering is quite expensive in terms of cost and time due to the hemispherical shape, earth-mound-type houses are often constructed without shuttering. The approach is simply to erect the steel reinforcement and cover this completely by spraying on concrete. However, this method has many disadvantages. The steel reinforcement must be of a design which is relatively dense and thus utilizes considerable material so that the concrete will adhere and not pass through the steel reinforcement. In addition, the concrete surfaces generated are very uneven—a disadvantage especially in regard to the interior since the wall must generally be plastered before being painted so as to obtain a smooth surface.

[0002] The patent literature contains a variety of proposed approaches for simplifying the construction of a hemispherical building. For example, the publications Swiss Patent 626 132, and U.S. Pat. No. 4,155,967 make known an inflatable membrane in the form of a balloon onto the exterior and interior surfaces of which concrete is sprayed, and which apparently obviates the need for separate shuttering. The disadvantage of this method, however, is that it creates problems in regard to the construction of large dome-shaped buildings, and that the method is also quite complex and expensive in that the membrane must be properly sealed against the ground to enable the balloon shape to be formed after air is blown in. Even relatively small leaks may mean that the membrane cannot be fully inflated, or collapses during hardening of the concrete—a result which at minimum requires subsequent expensive reworking.

[0003] German Patent 32 46 364 discloses a prefabricated earth-mound-type house in which prefabricated, parabolic or ellipsoidal steel-reinforced concrete components are linked together on a base plate and erected. The particular disadvantages of this are the transportation and erection costs. The steel-reinforced concrete components must be transported from the factory to the construction site on large trucks and erected with the aid of cranes. This procedure increases construction costs considerably. In addition, British Patent 2 028 395 discloses an igloo made of plastic foam material, for example, polystyrene or polyurethane, which is reinforced with a steel mesh. The igloo is erected from preferably eight wedge-shaped elements which are linked together by a slot-and-key joint and then sealed with a suitable mortar. The external face of the igloo may have a network onto which plaster is applied. The use of the plastic material results in the described igloo being relatively light—a feature which, however, entails a certain disadvantage in terms of stability. In addition, the slot-and-key joint of wedge-shaped elements is not very stable so that cracks may be created along the joints. Both German Patent 32 46 364 and British Patent 2 028 395 describe dome-shaped buildings constructed of prefabricated elements. In neither case, however, do these involve shuttering that can be removed after erection of the structure.

[0004] Shuttering, however, provides a number of advantages as compared with prefabricated construction elements. This method retains, for example, a certain flexibility during erection of the structure since the use of shuttering allows a number of design variations to be implemented—this not being possible with prefabricated elements. Additionally, more variation in the construction of the wall is possible since, for example, with shuttering it is possible to use concrete exclusively, or to apply an insulating layer along with it, or to incorporate the utility lines directly in place. All of this is possible when using shuttering without any additional load and without any additional expense, whereas with prefabricated components industrial mass production is desirable which makes the implementation of individual requirements much more expensive. As outlined above, known shuttering systems are poorly suited for construction of a hemispherical house. An individual shuttering must be erected and then destroyed for each individual hemispherical building.

[0005] An aluminum shuttering which is reusable is known from German Patent 44 40 959. Here shuttering segments are cut out in the circular-radial hemispherical form and held together by strong bolts. However, no additional details may be gleaned from this Offenlegungsschrift [unexamined patent application].

[0006] Thus, there remains the problem of how to provide shuttering to construct a hemispherical building for which the shuttering is simple, is not complicated to erect, and is reusable. In addition, a method must be provided to create the shuttering for the construction of a hemispherical house.

[0007] This problem is solved by a shuttering element according to claim 1 and a method according to claim 9. Preferred embodiments are the subjects of the subclaims.

[0008] The shuttering element according to the invention which is provided for constructing a hemispherical building has ribs projecting along its circumference at least at the side edges, which ribs extend into the later interior of the building. These projecting ribs, which may also be discontinuous in certain regions, may be used to quickly, simply and stably join the shuttering elements to form a complete shuttering. To achieve this, at least two shuttering elements are brought into contact so that they are joinable at the ribs projecting into the building interior. To this end, snap-on fasteners are preferably provided, for example in the form of clamps or socket pins, so as to allow rapid erection of the shuttering.

[0009] An additional feature is that the projections deviate somewhat from the vertical in relation to the main body of the shuttering elements, for example, by 1° to 10°. This feature allows for a better fit of the shuttering elements. The shuttering elements according to the invention preferably have a wedge shape, the shuttering elements being increasingly tapered, or following a conical line, from the base to the peak of the later hemisphere. Another feature is that the individual shuttering elements are not flat, but are instead curved in order to achieve a more uniform dome shape. In order to be able to integrate windows, doors and other openings in the building, shuttering elements are provided, the shape of which may be matched from the outside to the wedge-shaped primary shuttering elements just described. The surface of these special shuttering elements increases toward their top sides in order to allow for windows and doors projecting from the hemispherical building in the manner of dormer windows.

[0010] The preferred material for the shuttering elements according to the invention is glass-fiber-reinforced plastic which achieves a notable light-weight quality and ease of handling. An additional feature is that the lateral ribs are made of metal, preferably aluminum, so as to achieve sufficiently high strength. Another feature is that not only the projecting ribs but the entire shuttering element may be composed of aluminum. This greatly facilitates fabrication of the shuttering elements since the ribs may be formed from the shuttering bodies by folding or bending. Another feature is that insulation material may be detachably applied to the shuttering element according to the invention, for example by adhesive bonding. In this approach, insulation material may be applied directly onto the shuttering element before the concrete is sprayed on—with the result that thermal and/or sound insulation for the building can be already obtained at the stage of erecting the carcass. However, another possibility is to apply the concrete first and the insulating layer next; it is also possible to place the concrete between two insulating layers, or conversely, to place the insulation between two concrete layers.

[0011] A principal advantage of the shuttering element according to the invention is its reusability. After the concrete, either sprayed on or applied manually, has hardened, the shuttering elements may be removed, cleaned and reused. Due to the ribs extending into the building interior, the described shuttering is quick and easy to erect, yet remains stable; and generally, no tools are required to accomplish this. Generally, only a hammer, lever, and screwdriver are all that is required. Furthermore, due to the low weight, no type of supports are required; in principle, two workers may erect the shuttering for a complete earth-mound-type house without great effort since the ribs projecting toward the interior of the building used to connect the shuttering elements are readily accessible. This is especially advantageous since the surface formed by the concrete is also quite smooth due to the excellent fit of the shuttering elements according to the invention—with the result that no application of plaster is required, and the walls need only be painted. This means that a complete work step in the production of a mound-type house is eliminated. The elimination of this work step is extremely advantageous since the application of plaster to curved walls requires considerable time and labor, and is therefore very expensive. The production costs for an earth-mound-type house or similar hemispherical building are thus drastically reduced.

[0012] In the method according to the invention for constructing a hemispherical building, the described shuttering elements are linked together, preferably on a base plate. Erection of the shuttering elements is accomplished by bringing the shuttering elements into contact with each other and connecting them by the projecting ribs forming the contact surfaces at their side edges, specifically by snap-on fasteners. The main shuttering elements used are the wedge-shaped primary elements. In locations at which door or window openings are provided, suitable special shuttering elements in the form of dormers are used.

[0013] After the shuttering work is complete, the desired materials are applied, the first being specifically a steel reinforcement in order to enhance the stability of the finished building. Concrete is subsequently sprayed on, this application being possible in layers as required. Stiffening of the building may also be achieved by employing fiber-reinforced concrete, thereby eliminating the need for the steel reinforcement. In place of the concrete, a curable plastic compound such as polystyrene or polyurethane may be used. In addition, an insulation material may be applied directly to the shuttering using, for example, adhesive strips. Concrete is then applied to the insulation material, as just described. A steel reinforcement may be provided here as well.

[0014] The shuttering elements may be sprayed or smeared with form oil before the application of concrete to facilitate subsequent release of the hardened concrete. After the concrete or other material used has hardened, the shuttering is removed by detaching snap-on fasteners from the inside and removing the shuttering. The process of stripping the complete building is also a simple and labor-saving procedure since the elements may be removed gradually. Since no supports or braces are needed to construct the hemispherical building, the stripping process goes very quickly.

[0015] The invention is explained and described in more detail below based on the drawings.

[0016]FIG. 1 is a top view of a shuttering element according to the invention;

[0017]FIG. 2 is a side view of the shuttering element according to the invention as indicated by arrow II in FIG. 1;

[0018]FIG. 3 is a cross-section along line III in FIG. 2;

[0019]FIG. 4 is a cross-section through the joint of two adjacent shuttering elements;

[0020]FIG. 5 is a cross-section through another embodiment of the joint of two adjacent shuttering elements;

[0021]FIG. 6 is a side view of an embodiment of a special shuttering element;

[0022]FIG. 7 shows an embodiment of the wall structure of an earth-mound-type house in cross-section;

[0023]FIG. 8 is a top view of the shuttering; and

[0024]FIG. 9 is an overall side view of the completed hemispherical house.

[0025]FIG. 1 is shuttering element 1 according to the invention. Shuttering element 1 has a wedge shape which tapers from the bottom end 3 of shuttering element 1 up to the front end 2. When the shuttering element 1 according to the invention is mounted, front end 2 points to the peak of the hemisphere, while bottom end 3 rests on a base plate. In addition, shuttering element 1 according to the invention has two side edges 4 and 5. When multiple shuttering elements 1 are mounted, the adjacent shuttering elements abut at their side edges 4 and 5. At least along these side edges 4 and 5, the shuttering element 1

[0026] according to the invention has ribs 10, at least in sections, (see FIGS. 2 through 5) which create the joint of the individual shuttering elements 1, thereby erecting a hemispherical house as shown in FIGS. 8 and 9.

[0027] In order to achieve a uniform curvature of the building, shuttering elements 1 are preferably of a curved design, as indicated by a fold line 6. Multiple shuttering elements 1 of this type are required to produce a hemispherical building. For this reason, shuttering elements 1 each correspond to an angle à of the circle of the base surface. A hemispherical building may preferably be shuttered using twenty of the shuttering elements 1 according to the invention so that the angle à is 18ø. In additional to this preferred embodiment with an angle à of 18ø, and thus a segment number twenty, any other number of segments, and thus any other an angle of any degree may be used which allows a round building to be created. The front ends 2 here remain and form an opening or a skylight at the peak of the hemispherical building.

[0028] The curved shape of shuttering element 1 is clearly evident in FIG. 2. FIG. 2 is a side view (as indicated by arrow II) of shuttering element 1. The top side 7 of shuttering element 1 points toward the exterior of the building, while the bottom side 8 points to the building interior. Bottom end 3 rests on the base plate, while front end 2 points toward the peak of the hemisphere. It is preferable that section 9 facing the base plate is designed to be approximately vertical to the base plate. This section 9 identified as a jamb wall allows even the lower region of the hemispherical structure to be effectively utilized. In FIG. 2, the rib 10 is also indicated at side edge 4. This rib projects beyond the low side 8 of shuttering element 1 and thus points toward the later interior of the building.

[0029]FIG. 3 is an enlarged cross-section along intersecting line III-III in FIG. 2. Here the projection of rib 10 at side edge 4 of shuttering element 1 is clearly evident. Rib 10 may have a plurality of bore holes or guides 11 which serve to accommodate insertion of the pin fasteners or other snap-on fasteners.

[0030]FIGS. 4 and 5 show the joint of two shuttering elements 1 and 1′, one element being of identical construction and identified with a prime to distinguish it. Shuttering elements 1 and 1′ are brought into contact so that they contact each other along their side edges 5 and 4′. This causes ribs 10 and 10′ to abut each other. Shuttering elements 1 and 1′ are now connected by a strong clamp 12 (FIG. 4) or a pin connector 13 (FIG. 5) or similar snap-on fastener (for example, cotter pin). This action fixes and secures shuttering elements 1 and 1′ precisely in both position and alignment. FIG. 4 shows a formed rib 10, 10′ which is formed on during fabrication of shuttering elements 1, 1′, for example, during rolling or pressing of an aluminum sheet.

[0031] In contrast, FIG. 5 shows a rib 10, 10′ which is attached after the primary body 14, 14′ of shuttering elements 1, 1′ is formed. To this end, the projecting rib 10, 10′ is superimposed, for example, in the form of a metal strip, onto the side edges of shuttering body 14, 14′, and then attached there, for example, using rivets or other fastening means 15, 15′. FIG. 5 furthermore shows that ribs 10, 10′ deviate from the vertical of primary body 14 of shuttering element 1 by an angle á. Angle á is specifically 1-10ø. This slight deviation of projection 10 by the angle á is advantageous since it allows an especially precise fit to be achieved when the individual shuttering elements 1, 20 are joined. In this way, uniform concrete surfaces are generated which subsequently require only painting.

[0032]FIG. 6 is a side view of shuttering element 20. Shuttering element 20 is a special shuttering element and is provided to create an opening in the hemispherical building. The shuttering element 20 shown in FIG. 6 functions, for example, as the shuttering for a door. To produce a window instead of a door, a shuttering element of similar design may be used, for example by eliminating the section below line 21. Matching shuttering element 1, this shuttering element 20 has a bottom end 23, a front end 22 for the window or door area, and a lateral periphery 24 (see also FIG. 9), a land 25 facing the cavity and connecting to the main shuttering (see FIG. 8), and a top side 27. Preferably, ribs 10 are formed along the circumference of shuttering element 20, specifically along sides 23, 25 and 27 (dotted line on drawing), as described above for shuttering element 1. A cap element 26 (see also FIG. 9) is placed onto top side 27 of shuttering element 20 and is preferably covered with an insulation layer 30 so as to receive concrete poured onto it as indicated by line 32.

[0033]FIG. 7 is a cross-section through the structure of the wall of a hemispherical building. The shuttering element 1 is shown here on the inside 36 (here the left side) of the building. It consists of the actual shuttering body 14 with top side 7 and bottom side 8. Rib 10 with guides 11 is also visible. An insulation layer 30 is attached to shuttering element 1 by adhesive bonds 31.

[0034] This insulation layer 30 may consist of any known insulation material. A concrete layer 32 is then applied to insulation layer 30. Anchoring means 33, 34, 35 are provided to connect concrete layer 32 to insulation layer 30, wherein anchoring means 33, 34, 35 may also take the form of hooks or barbs. Insulation layer 30 is thus anchored to concrete layer 32 so that shuttering element 1 may be detached at adhesive bond 31 when the shuttering is removed.

[0035] The method according to the invention is described with reference to FIGS. 1 through 7. After setting up the base plate, wedge-shaped shuttering elements 1 are erected side-by-side to form a hemisphere. Shuttering elements 1 are joined with and to each other by projecting ribs 10 which run at least along sides 4 and 5. The joint is achieved using snap-on fasteners such as U-shaped clamps 12 which surround ribs 10, or pin connectors 13. The special shuttering elements 20 are then mounted from the outside at those locations where the door or window cut-outs will be provided subsequently. After shuttering elements 1 to form the hemisphere (see top view in FIG. 8) and shuttering elements 20 for the windows are erected, concrete or other hardening materials or insulating compounds may be directly sprayed on, or an intermediate layer composed of an insulation material is used. After the layers have been applied and the concrete compound has hardened, the shuttering is removed from the building interior. To this end, the snap-on fasteners, such as clamps 12 or pin connectors 13, are detached by moderate hammer blows and shuttering elements 1 or 20 are removed from the wall of the hemispherical building carcass, while the possible insulation layer 30 remains securely anchored to the concrete layer 32. The result is a hemispherical house as in FIG. 9 (side view). 

1. Shuttering element for constructing a hemispherical building, characterized in that the shuttering element (1, 20) has ribs (10) projecting toward the building interior (36) along the side edges (4, 5).
 2. Shuttering element according to claim 1, characterized in that at least two shuttering elements (1, 20) are interconnectable by snap-on fasteners (12, 13).
 3. Shuttering element according to claim 1, characterized in that the ribs (10) deviate from the vertical relative to the shuttering element (1), specifically at an angle (β) from 1-10°.
 4. Shuttering element according to one of claims 1 through 3, characterized in that the shuttering element (1) has a tapered shape, specifically a wedge shape, from the base edge (3) to the top edge (2).
 5. Shuttering element according to one of claims 1 through 4, characterized in that the shuttering element (1) corresponds to an 18° sector of the circle forming the ground surface of the hemispherical building.
 6. Shuttering element according to one of claims 1 through 5, characterized in that the shuttering element (1) is composed of a material of low density, specifically glass-fiber-reinforced plastic or aluminum.
 7. Shuttering element according to claim 6, characterized in that the ribs (10) are composed of metal, specifically aluminum.
 8. Shuttering element according to one of the foregoing claims, characterized in that an insulation layer (30) may be attached, specifically, adhesively bonded, to the exterior (7) of the shuttering element (1).
 9. Method of shuttering for constructing a hemispherical building, wherein multiple shuttering elements (1, 20) are linked together and connected to form complete shuttering, concrete (32) is subsequently applied to the exterior (7) of the shuttering elements (1, 20), and after the concrete (32) has hardened the shuttering elements (1, 20) are removed from the building interior (36), characterized in that the shuttering elements (1, 20) are joined by ribs (10) using snap-on fasteners (12, 13).
 10. Method according to claim 9, characterized in that an insulation layer (30) is applied to the exterior (7) of the shuttering elements (1, 20), specifically bonded on, before concrete (32) is applied thereto. 